Friendly JSON serialization (Was: Annotation Serializations)

Second item from the discussion seems to be the availability of a web
developer friendly JSON serialization.

Some background -- we have been asked for JSON serializations for at least
3 years. Here is one such request of many, from 2011:
https://groups.google.com/forum/#!topic/oac-discuss/CSq9Jsdd3zk where we
kicked the can down the road waiting for JSON-LD to come along.

Which it has, and is the recommended serialization for Open Annotation.

So the question is not the JSON serialization's existence, but its
developer friendliness, and whether we can do any better while remaining
conformant with the JSON-LD specification.

I think that would be a great discussion to have, or rather to restart, as
it was brought up in point 2 of this thread:
http://lists.w3.org/Archives/Public/public-openannotation/2013Apr/0015.html


Rob



On Sun, Jan 19, 2014 at 5:25 AM, Ivan Herman <ivan@w3.org> wrote:

> Hi Doug, everybody,
>
> I try to understand what you mean... Are we talking about some sort of a
> family of use case templates? Or a formal and thorough serialization
> specification in HTML, ie, some sort of a specialized RDFa? The latter may
> be quite a lot of work... (having gone through the RDFa exercise myself). A
> template library could probably be done more easily; for RDF usage one
> could then make some sort of a preprocessor to RDFa, and then let the
> existing RDFa processors take over.
>
> I looked at your example, and, for the purpose of the discussion, I did
> re-cast it into RDFa Lite. I *think* it is what you meant but probably not
> exactly; I did remove the internal properties for Bush because you annotate
> <http://example.com/sourcedoc.html> and not the snippet and, I must
> admit, I was not sure how that 'cite' would translate into OA (I am not
> sure it can, it may need some additional properties). I was also not sure
> whether the tagging is properly mapped onto the OA. With that, I believe
> the snippet below is more-or-less correct:
>
>     <aside vocab="http://www.w3.org/ns/oa#" typeof="Annotation">
>       <p>
>         <a property="annotatedBy" href="http://example.com/people/shepazu"
> typeof="foaf:Person">
>            <span property="foaf:name">Shepazu</span>
>          </a>
>       </p>
>       <time property="annotatedAt" datetime="2014-01-14T01:28:22-0500">
>         <a href="http://example.com/annotations/shepazu-1389680902"
>            title="1:28 AM - 14 Jan 2014">A few minutes ago</a>
>       </time>
>
>       <blockquote property="hasTarget"
>                   resource="http://example.com/sourcedoc.html"
>                   cite="http://example.com/sourcedoc.html"
>                   data-prefix="essential feature of the memex. "
>                   data-suffix=" When the user is building a tra" typeof="">
>         <p>The process of tying two items together is the important
> thing.</p>
>         <footer>
>           - <cite>
>                  <a href="http://en.wikipedia.org/wiki/Vannevar_Bush">
>                     <span>Vannevar Bush</span>
>                  </a>
>             </cite>
>         </footer>
>       </blockquote>
>       <p property="hasBody" typeof=""><span
> property="rdf:value">Annotations are at the Web's core.</span></p>
>       <ul property="hasBody" typeof="SemanticTag">
>          <li property="rdf:value">annotations</li>
>          <li property="rdf:value">web</li>
>          <li property="rdf:value">standards</li>
>       </ul>
>     </aside>
>
> There are some quirks, because I tried to keep it within RDFa Lite (mainly
> the usage of @typeof=""). Also, RDFa+HTML5 does not understand the @cite
> attribute in <blockquote>; it could be easily added to RDFa Lite, if there
> is a great demand for it, but that would require some extra spec rounds.
> Hence the @resource attribute that repeats the URI :-(
>
> I believe the correct mapping to OA is to have two different bodies; one
> is your remark, the other are the tags. (I have added the generated Turtle
> at the end, where I have taken out some statements that an RDFa processor
> generates into the resulting graph, but is irrelevant for us here.)
>
> Yes, it is slightly more complex than your thing. (Note that, I believe,
> mapping this to microdata would be even more complex; indeed, microdata
> does not allow mixing different vocabularies, like I do here with OA and
> foaf and rdf.) I am not sure which direction one should/could take in
> simplifying it.
>
> But... I have also generated a JSON-LD code from the RDFa above, and then
> simplified it (my JSON-LD knowledge is not perfect, but I have checked it
> by a JSON-LD checker):
>
> {
>     "@context": "http://www.w3.org/ns/oa.json",
>     "@type": "Annotation",
>     "annotatedAt": "2014-01-14T01:28:22-0500",
>     "annotatedBy": {
>         "@id": "http://example.com/people/shepazu",
>         "name": "Shepazu",
>         "@type" : "Person"
>     },
>     "hasBody": [
>         {
>             "value" : "Annotations are at the Web's core."
>         },
>         {
>             "@type": "SemanticTag",
>             "value": [
>                 "web",
>                 "standards",
>                 "annotations"
>             ]
>         }
>     ],
>     "hasTarget": "http://example.com/sourcedoc.html"
>
> }
>
> with the supposition that the oa.json contains a lot of information on
> mapping the data to RDF that can be hidden from the end user, like the fact
> that 'value' or 'Person' are terms from another vocabulary (RDF and FOAF,
> respectively). In this sense, JSON-LD is more flexible than RDFa. For a
> JSON user the only slightly unusual thing is the usage of the "@"
> character. The "@context" can also be omitted for those who do not want to
> care about RDF; actually, if used on the Web, the context can also be
> transferred through an HTTP header.
>
> I actually find the JSON-LD the simplest. And I begin to wonder whether we
> really have annotations themselves marked up in HTML, or, more exactly,
> whether that is a major use case. I have the impression that annotations
> are built up through user interactions and are stored somewhere, and the
> storage would not necessarily happen in HTML but, rather, in JSON (e.g., in
> a JSON database, or something like that).
>
> (Note that it is also possible to embed a JSON(-LD) snippet into an HTML
> file[1]. This is an approach that the schema.org people have also done
> for some of their clients[2].)
>
> Ivan
>
> [1] http://www.w3.org/TR/json-ld/#embedding-json-ld-in-html-documents
> [2] http://blog.schema.org/2013/06/schemaorg-and-json-ld.html
>
>
> P.S. Here is the turtle:
>
> @prefix foaf: <http://xmlns.com/foaf/0.1/> .
> @prefix oa: <http://www.w3.org/ns/oa#> .
> @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
>
> <http://example.com/people/shepazu> a foaf:Person ;
>     foaf:name "Shepazu" .
>
> [] a oa:Annotation ;
>     oa:annotatedAt "2014-01-14T01:28:22-0500" ;
>     oa:annotatedBy <http://example.com/people/shepazu> ;
>     oa:hasBody
>         [ rdf:value "Annotations are at the Web's core." ],
>         [ a oa:SemanticTag ;
>             rdf:value "annotations", "standards", "web"
>         ] ;
>     oa:hasTarget <http://example.com/sourcedoc.html> .
>
>
> On 19 Jan 2014, at 24:29 , Doug Schepers <schepers@w3.org> wrote:
>
> > Hi, folks–
> >
> > The work this group has done so far is excellent. I think the data model
> is really solid. I'd like to see it applied broadly, not just for
> annotations proper, but also for comments, footnotes, bookmarks, and other
> similar things along the same lines.
> >
> > And I'd like annotations to be supported by browsers natively; I think
> that would dramatically increase their usage and usability.
> >
> > To that end, I'd like to introduce a few topics that I think can build
> on the data model, and couch it in terms that the average web developer can
> easily understand and apply, and which browser vendors might get behind.
> >
> > The first of these is some suggestions on different serializations, for
> those who aren't interested in the RDF aspects (yes, hard to believe, but
> such people do exist!).
> >
> > Here's a (terrible, almost certainly incorrect) strawman for an HTML
> serialization of an annotation (consider it the bastard child of
> OpenAnnotation and Twitter):
> >
> > <aside vocab="http://www.w3.org/ns/oa#">
> >   <p>
> >     <a property="annotatedBy"
> >         href="http://example.com/people/shepazu"
> >         typeof="Person">
> >        <span property="name">Shepazu</span>
> >      </a>
> >   </p>
> >
> >   <time property="annotatedAt" datetime="2014-01-14T01:28:22-0500">
> >     <a href="http://example.com/annotations/shepazu-1389680902"
> >        title="1:28 AM - 14 Jan 2014">A few minutes ago</a>
> >   </time>
> >
> >   <blockquote property="hasTarget"
> >               cite="http://example.com/sourcedoc.html"
> >               data-prefix="essential feature of the memex. "
> >               data-suffix=" When the user is building a tra">
> >     <p>The process of tying two items together is the important
> thing.</p>
> >     <footer>
> >       – <cite>
> >                <a href="http://en.wikipedia.org/wiki/Vannevar_Bush"
> >                   typeof="Person">
> >             <span property="name">Vannevar Bush</span>
> >                </a>
> >         </cite>
> >     </footer>
> >   </blockquote>
> >
> >   <p property="hasBody">Annotations are at the Web’s core.</p>
> >
> >    <ul>
> >      <li property="tag">annotations</li>
> >      <li property="tag">web</li>
> >      <li property="tag">standards</li>
> >    </ul>
> > </aside>
> >
> >
> > Another serialization could be in very lightweight JSON, for sockets
> interchange.
> >
> > All of these serializations should be defined in such a way that they
> are losslessly transformable into any of the other serializations; any
> missing data (for example, values omitted for brevity) should have default
> (or lacunae) values that are populated for other serializations that might
> need them, such as RDF.
> >
> > Thoughts?
> >
> >
> > Regards-
> > -Doug
> >
>
>
> ----
> Ivan Herman, W3C
> Digital Publishing Activity Lead
> Home: http://www.w3.org/People/Ivan/
> mobile: +31-641044153
> GPG: 0x343F1A3D
> FOAF: http://www.ivan-herman.net/foaf
>
>
>
>
>
>